The present invention relates to devices for providing a person with a sense of feel in a prosthetic or sensory impaired limb.
The present invention is directed to a method for providing sensory perceptions in a sensor system of a prosthetic device. The method comprises sensing an external operation magnitude from a plurality of sensor groups, each sensor group sensing a fraction of the external operation magnitude. A plurality of sensory inputs from the sensor groups is generated in response to the external operation. An electrical input signal with a magnitude also is generated. The electrical input signal is controlled with the plurality of sensory inputs to create a plurality of sensory output signals collectively having a stimulus with a collective stimulus magnitude corresponding to the electrical input signal magnitude. Each sensory output signal has a fraction of the stimulus magnitude corresponding to the fraction of the external operation magnitude sensed by one of the sensor groups. Each of the sensory output signals is transmitted to a designated one of a plurality of contacts through a designated one of a plurality of channels.
Still further, the present invention comprises a sensory feedback system for use with a prosthetic device. The sensory feedback system comprises a power source that is adapted to transmit an electrical input signal. Included are a plurality of sensors each operable to create a sensory inputs in response to an external operation thereon. Further, the sensory feedback system comprises a plurality of contacts each adapted to receive a sensory output signal. The sensory feedback system includes a plurality of channels each connected to one of the plurality of contacts and adapted to carry one of the sensory output signals to the contact to which it is connected. The sensory feedback system also comprises a control and processing center adapted to receive the electrical input signal from the power source and to receive the sensory inputs from the pressure sensors, to control the electrical input signal by applying the sensory inputs to the electrical input signal to create the sensory output signals, and to transmit the sensory output signals to the contacts through the channels.
Further still, the present invention comprises a sensory feedback system for a prosthetic device. The sensory feedback system comprises a power source adapted to transmit an electrical power signal and an electrical input signal, a control and processing center adapted to receive the electrical input signal and to transmit a plurality of sensory output signals, and a plurality of contacts each adapted to receive a designated one of the sensory output signals. The sensory feedback system also comprises a plurality of inductance-based pressure sensors each adapted to receive the electrical power signal, to change the electrical power signal to a sensory input signal representing pressure applied thereto, and to transmit the sensory output signal therefrom. Also comprising the sensory feedback system is a sensor controller adapted to route the electrical power signal to each inductance-based pressure sensor and to return the sensory input signal from each inductance-based pressure sensor to the control and processing center. The control and processing center processes the sensory input signals and the electrical input signal to create a plurality of sensory output signals each representing the pressure applied to at least one of the inductance-based pressure sensors. In addition, the control and processing center transmits the sensory output signals to the contacts.
In another aspect, the present invention is directed to a lower limb prosthesis. The lower limb prosthesis includes a leg portion including a socket for receiving a residual limb of an amputee. A foot portion is attached to the leg portion. The foot portion having a sole, and a pressure sensor is positioned under the sole of the foot to provide an electrical resistance in proportional response to pressure against the sole of the foot. A power source is included to generate an electrical power signal, and an electrical power signal conductor is included to conduct the electrical power signal from the power source to the pressure sensor. A control and processing center also is included. The control and processing center is adapted to respond to the electrical resistance in the pressure sensor, whereby the power source is deactivated in response to electrical resistance in the pressure sensor which is greater than a selected level of electrical resistance and whereby the power source is activated in response to electrical resistance in the pressure sensor which is less than the selected level of resistance. A residual limb contact is included to transmit the electrical power signal to the residual limb. In addition, a channel is included to conduct a sensory output signal from the pressure sensor to the residual limb contact.
In yet another aspect, the present invention is directed to a lower prosthesis. The lower limb prosthesis comprises a leg portion including a socket for receiving the residual limb of an amputee. A foot portion is attached to the leg portion, the foot portion having a sole with a heel and a ball of the foot. A first pressure sensor is position under the ball of the foot adapted to provide an electrical resistance in proportion to pressure against the ball of the foot with respect to total pressure, and a second pressure sensor is positioned under the heel adapted to provide an electrical resistance in proportion to pressure against the heel with respect to total pressure. A power source is included to generate electrical current having a magnitude. An electrical current conductor is included to conduct electrical current from the power source to the first and second pressure sensors.
The lower limb prosthesis further comprises a first residual limb contact adapted to transmit electrical to a first location on the residual limb. A first channel conducts electrical current from the first pressure sensor to the first residual limb contact. A second residual limb contact is included to transmit electrical to a second location on the residual limb. A second channel conducts electrical current from the second pressure sensor to the second residual limb contact. The lower limb prosthesis further comprises a control and processing assembly adapted to create a first and second sensory output signal collectively having a stimulus with a collective stimulus magnitude corresponding to the electrical current magnitude. Each sensory output signal has a fraction of the stimulus magnitude corresponding to the fraction of the pressure sensed by the respective sensors with respect to the total pressure.
In still another aspect, the present invention comprises an upper limb prosthesis. The upper limb prosthesis includes an arm portion including a socket adapted to receive the residual limb of the amputee. A hand portion is attached to the arm portion, the hand portion having at least one digit. A power source generates an electrical current. A pressure sensor is installed in the at least one digit to receive the electrical current, to provide an electrical resistance to pressure on the at least one digit, and to emit, in response to the pressure, an electrical signal in proportion to the intensity of pressure on the at least one digit.
The upper limb prosthesis further comprises a control and processing center adapted to convert the electrical signal from the pressure sensor to a stimulus, to deactivate the transmission of the stimulus to the residual limb in response to a predetermined period of lack of muscle activity in the residual limb, and to activate the transmission of the stimulus in response to muscle activity in the residual limb. A residual limb contact is provided to receive the stimulus from the control and processing center and to transmit the stimulus to the residual limb.
The present invention is also directed to a system for providing sensory feedback to a person having a prosthetic device The system comprises a plurality of sensors. Each of the sensors is located at a respective area of the prosthetic device and has a sensor characteristic to define a plurality of sensor characteristics. Each of the sensor characteristics indicates a degree of exposure of the respective sensor to an external influence. The sensor characteristic of each of the sensors defines a sensor fraction of the total of the sensor characteristics.
The system further comprises a plurality of output elements, each of the output elements corresponding to one of the sensors and being in communication with a sensory-perceptive area of the person. The system also includes a control and processing center operatively connected to the sensors and to the output elements. The control and processing center produces a sensory output in each of the output elements to define a plurality of sensory outputs. The sensory output of each of the output elements defines an output fraction of the total of the sensory outputs. The output fraction is substantially equal to the sensor fraction of the corresponding sensor.